This is a great plugin and very much needed especially for my project. However, I am having some issues after applying the upgrade. I am using this plugin on WPMU 2.8.4 with the multi-db structure, and I get the following message in the backend, "WP invites table could not be installed! Please check database permissions. Error:" Also, on wp-signup.php, the rest of the signup form is cutoff after "Email Address", which is due to the plugin.